A new study finds that from 1990 to 2007, nearly a million Americans wound up in emergency rooms with weight-training injuries, and that annual injuries increased more than 48 percent in that period.

About 82 percent of the 970,000 people injured were men, according to the study, which appeared in the April issue of The American Journal of Sports Medicine. (The researchers used data from a national injury surveillance database.) But the annual number of injuries in women increased faster — by 63 percent, compared with 46 percent among men — perhaps because weight training is growing more popular with women.

Women were more likely to injure their feet and legs, while men’s injuries were more common in the trunk and hands; men had more sprains and strains, and women had more fractures.

People were most often injured by dropping weights on themselves, crushing a body part between weights or hitting themselves with the equipment. Overexertion, muscle pulls and loss of balance accounted for about 14 percent of emergency room visits. More than 90 percent of the injuries occurred while using free weights rather than weight machines.

Under 2 percent of the injuries resulted in hospitalization, but a few were fatal: the researchers estimate that 114 deaths nationwide were related to weight training over the 18-year period.

Estimates of the number of people who use weights vary, but according to the National Sporting Goods Association, a trade group, 34.5 million people participated in weight training in 2009.

“We want people to continue to use weight training as part of their physical routine,” said a co-author of the study, Christy L. Collins, a senior research associate at Nationwide Children’s Hospital in Columbus, Ohio. But, she added, they “should receive proper instruction and use proper techniques for their lifts.”

“As researchers,” she went on, “we want to learn more about these injuries so that we can develop targeted preventive measures.”

[Source: nytimes;com]